1. Field of the Invention
The present invention regards a monitoring device for tyres for vehicle wheels.
The present invention also regards a tyre for vehicle wheels provided with said monitoring device.
The present invention also regards a method for installing an electronic unit in a tyre.
2. Description of the Related Art
The need to monitor the operating conditions of the tyres and possibly track the time evolution of representative parameters of such operation has been assuming increasing importance by virtue of the requirement of increased safety imposed on vehicles by clients and/or by national directives/legislation.
The parameters generally considered can be, for example, temperature, pressure, distance travelled by the tyre (and/or number of revolutions), load acting on the tyre, as well as parameters which derive on mathematical processing that can be executed on the basis of signals detected by sensors placed inside the tyres.
Such parameters can also be used for identifying particular conditions in which the tyre and/or the vehicle are found, such as wear conditions, aquaplane conditions etc. and, more generally, for the monitoring of the forces acting on the tyre during its rolling (e.g. on the road surface).
For such purpose, inside the tyre an electronic unit can be mounted, which can comprise at least one sensor, a control unit and/or data storage unit (such as a microprocessor), a power supply system and an antenna; the latter has the task of enabling the exchange of radiofrequency signals with the devices mounted on board the vehicle.
The electronic unit can be mounted on the inner surface of the tyre by means of a connecting member.
Documents U.S. Pat. No. 6,030,478, U.S. Pat. No. 6,386,251, U.S. Pat. No. 6,860,303, U.S. Pat. No. 7,009,506, EP 1948452, U.S. Pat. No. 7,908,918 and U.S. Pat. No. 7,874,205 show several techniques by means of which an electronic unit can be associated with the inner surface of the tyre.
The Applicant has observed that the systems of known type are not entirely safe and reliable. Indeed, such systems allow, or at least do not prevent the electronic unit from being removed after having been fastened to the tyre.
According to the Applicant, this factor can be extremely disadvantageous, since the data detected and stored by means of the electronic unit are typically used also for determining the overall distance travelled by the tyre.
Such data can also be employed for the optimization of the set-up of passive control systems of the vehicle, e.g. systems adapted to verify the suitability between the type of tyre actually installed and the types of tyre provided and considered acceptable, as well as active control systems, which use, among other parameters, those identifying the type of tyre for actively operating on the operation of the vehicle, in order to maintain the latter in safety conditions (e.g. ABS, ESP, etc.).
The removal and substitution of the electronic unit can thus enable falsification of this data, allowing ill-intentioned subjects to illegally take advantage of the discrepancy between the data signalled by the electronic unit installed in substitution of that original and the actual travel data of the tyre, and/or significantly limiting the safety in the active and passive controls of the vehicle dynamics.